What Release Film / Peel Ply to use for Smooth Finish on Carbon Fiber Fabric Wet Lay-Up / Vacuum Bagging

[Gary Wilkinson]

Hello,

I am the newest of a newbie, but have spent considerable time reviewing all the available videos, etc. to learn as much as possible before placing an order for everything I need to execute my vacuum bagging plan.  Just need one simple clarification before proceeding.  The proposed set-up will be a wet lay-up (3 layers) on both sides of a part cut from a carbon fiber plate purchased from Rock West Composites, with vacuum bagging to ensure the best bond and greatest strength.  I want the finished part to have the best appearance and smoothest finish on both sides.  Will be using West System epoxy resin / hardener.  All work will be done at room temperature.

 

My needed clarification is ..... it seems that the Rock West Composites Peel Ply (Econo Ply J or COMPOFLEX) would leave a textured or roughened surface best for later sanding, bonding, or painting.  That is NOT how I want the finished surface.  So, I don't think I want Peel Ply on the surfaces of the part.  Can I use a Release Film, with holes for porosity to move excess resin, and have the desired final result on the finished part?  Yes, I will be using Breather Fabric on top of the Release Film.

If Release Film is the solution, which one (RELEASE EASE 234TFP or HIGH TEMPERATURE RELEASE Ply) would be preferable.

Thank you in advance for your help!

Gary Wilkinson

[lo_0l]

On 5/3/2024 at 3:15 PM, Gary Wilkinson said:

Hello,

I am the newest of a newbie, but have spent considerable time reviewing all the available videos, etc. to learn as much as possible before placing an order for everything I need to execute my vacuum bagging plan.  Just need one simple clarification before proceeding.  The proposed set-up will be a wet lay-up (3 layers) on both sides of a part cut from a carbon fiber plate purchased from Rock West Composites, with vacuum bagging to ensure the best bond and greatest strength.  I want the finished part to have the best appearance and smoothest finish on both sides.  Will be using West System epoxy resin / hardener.  All work will be done at room temperature.

 

My needed clarification is ..... it seems that the Rock West Composites Peel Ply (Econo Ply J or COMPOFLEX) would leave a textured or roughened surface best for later sanding, bonding, or painting.  That is NOT how I want the finished surface.  So, I don't think I want Peel Ply on the surfaces of the part.  Can I use a Release Film, with holes for porosity to move excess resin, and have the desired final result on the finished part?  Yes, I will be using Breather Fabric on top of the Release Film.

If Release Film is the solution, which one (RELEASE EASE 234TFP or HIGH TEMPERATURE RELEASE Ply) would be preferable.

Thank you in advance for your help!

Gary Wilkinson

For the very best finish you're going to want to wet sand and apply a 2K high gloss clear coat 

Can you explain what you're doing with the plate a bit better? Are you trying to increase the thickness of the plate or are you trying to change the finish?

[Gary Wilkinson]

Hello,

Thanks for your follow-up!  I cut (wet tile saw) 3 rocket fins out of the purchased plate and used a high quality epoxy to bond those fins to the airframe of my rocket.  Then, sanded, cleaned (lint free cloth and acetone) to achieve a good "water break" surface on all six faces (both sides of 3 fins) of the fins, along with the relevant section of Carbon Fiber airframe.  Then went through the wet lay-up process (3 layers @ 0 degrees, 45 degrees, and 0 degrees) with the cut Carbon Fiber fabric, using West Systems resins, and finished with High Temp (450 F) perforated Release Ply and Breather Fabric, before bagging.  All done at a cool room temperature indoors!  Waited about 4 hours for the resin to reach a "leather" texture, disassembled the set-up and stripped off the Breather and Release Ply.  Frigging awesome result!!!  I achieved exactly the finish and final thickness I hoped for on the fins.  Will certainly require some finish touches on the leading and trailing edges of the fins for optimum aerodynamics, but that is easily accomplished.  As you mentioned I can see that the very best final finish will require wet sanding (800, 1000, 1500, 2000 grit is my plan), finished with a hard clear coat.  In the rocket business smoother is faster, and faster is higher!

Fortunately, I did a LOT of preliminary work to ensure a reasonably smooth process.  Did EVERYTHING possible ahead of the layup, and practiced the process over and over prior to the actual execution.  The use of electric scissors, and 3M 77 on wax paper to keep the cut pieces of carbon fabric from separating was pure genius!  A 2nd person to mix resin and hand me the cut sections of carbon fiber fabric (on wax paper), orientated correctly, was super helpful. 

It took me way longer to build the wood jig for the lay-up procedure, along with the vacuum bag, than the lay-up and bagging process itself.

My original question was just too basic, as it was obvious that a smooth surface like the Release Ply would certainly yield a better finished (smoother) surface than the Peel Ply.  My trivial question was probably a waste of time to your community!

Regards,

Gary

[lo_0l]

6 minutes ago, Gary Wilkinson said:

Hello,

Thanks for your follow-up!  I cut (wet tile saw) 3 rocket fins out of the purchased plate and used a high quality epoxy to bond those fins to the airframe of my rocket.  Then, sanded, cleaned (lint free cloth and acetone) to achieve a good "water break" surface on all six faces (both sides of 3 fins) of the fins, along with the relevant section of Carbon Fiber airframe.  Then went through the wet lay-up process (3 layers @ 0 degrees, 45 degrees, and 0 degrees) with the cut Carbon Fiber fabric, using West Systems resins, and finished with High Temp (450 F) perforated Release Ply and Breather Fabric, before bagging.  All done at a cool room temperature indoors!  Waited about 4 hours for the resin to reach a "leather" texture, disassembled the set-up and stripped off the Breather and Release Ply.  Frigging awesome result!!!  I achieved exactly the finish and final thickness I hoped for on the fins.  Will certainly require some finish touches on the leading and trailing edges of the fins for optimum aerodynamics, but that is easily accomplished.  As you mentioned I can see that the very best final finish will require wet sanding (800, 1000, 1500, 2000 grit is my plan), finished with a hard clear coat.  In the rocket business smoother is faster, and faster is higher!

Fortunately, I did a LOT of preliminary work to ensure a reasonably smooth process.  Did EVERYTHING possible ahead of the layup, and practiced the process over and over prior to the actual execution.  The use of electric scissors, and 3M 77 on wax paper to keep the cut pieces of carbon fabric from separating was pure genius!  A 2nd person to mix resin and hand me the cut sections of carbon fiber fabric (on wax paper), orientated correctly, was super helpful. 

It took me way longer to build the wood jig for the lay-up procedure, along with the vacuum bag, than the lay-up and bagging process itself.

My original question was just too basic, as it was obvious that a smooth surface like the Release Ply would certainly yield a better finished (smoother) surface than the Peel Ply.  My trivial question was probably a waste of time to your community!

Regards,

Gary

No problem Gary,

It's wonderful to have you here and part of the community! All skill levels are welcome and encouraged to join and participate here 🙂

Do you have pictures of your project? It sounds really neat.